fun main(args: Array<String>) {
    val input = """ABCDE This is some text.
This is more text. ABCDE, ABCDE.
ABCDE And this is [ABCDE] still more text."""

    val regex = Regex("ABCDE")
    var count = 1
    val result = regex.replace(input) {
        _ -> "X" + count++
    }
    println(result)
}